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Water stable isotopes in central Antarctic ice cores are critical to quantify past temperature changes. Accurate temperature reconstructions require to understand the processes controlling surface snow isotopic composition. Isotopic fractionation processes occurring in the atmosphere and controlling snowfall isotopic composition are well understood theoretically and implemented in atmospheric models. However, post-deposition processes are poorly documented and understood. To quantitatively interpret the isotopic composition of water archived in ice cores, it is thus essential to study the continuum between surface water vapour, precipitation, surface snow and buried snow. Here, we target the isotopic composition of surface snow, precipitation and water vapour at Concordia Station, where the oldest EPICA Dome C ice cores have been retrieved. While snowfall and surface snow sampling is routinely performed, accurate measurements of surface water vapour are challenging in such cold and dry conditions. New developments in infrared spectroscopy enable now the measurement of isotopic composition in water vapour traces. Two infrared spectrometers have been deployed at Concordia, allowing continuous, in situ measurements for one month in December–January 2014–2015. Comparison of the results from infrared spectroscopy with laboratory measurements of discrete samples trapped using cryogenic sampling validates the relevance of the method to measure isotopic composition in dry conditions. We observe very large diurnal cycles in isotopic composition well correlated with temperature diurnal cycles. Identification of different behaviours of isotopic composition in the water vapour associated with turbulent or stratified regime indicates a strong impact of meteorological processes in local vapour/snow interaction. Even if the vapour isotopic composition seems to be, at least part of the time, at equilibrium with the local snow, the slope of δD against δ18O prevents us from identifying a unique origin leading to this isotopic composition.

Gastric cancer is the second most common cancer worldwide. The involvement of ROS (reactive oxygen species) in the pathogenesis of gastric malignancies was well know. Many human tumors have shown significant changes in the activity and expression of SOD that might be correlated with survival and clinical-pathological parameters for the prognosis of human carcinoma. Aim of this study is the detection of the MnSOD and CuZnSOD activity and expression in adenocarcinoma, Helicobacter Pilory (HP), autoimmune-atrophic-gastrite (GTA) and healthy tissues. A total of 21 gastric specimens (5 adenocarcinoma, 9 healthy, 5 HP and 2 GTA) collected during endoscopy or resected during surgery were extracted in phosphate buffer and used to determine the SOD activity and expression by spectrophotometric and western blotting assay. As regards to the carcinoma tissues, the trend of the activity of MnSOD is over 9-fold higher and 2.5-fold higher which respect to CuZnSOD in tumors and HP, respectively. On the contrary in healthy tissues and GTA the CuZnSOD shows a similar or major activity than MnSOD and each isoforms represent nearly the 50% of total SOD activity. After immunoblotting detection of SOD isoforms, MnSOD seem lightly more expressed in adenocarcinoma and HP cases respect to healthy tissues and GTA. SOD activity assay can provide a specific and sensible method of analysis that allows to differentiate healthy tissue from tumour, GTA and HP. The ratio of MnSOD and CuZnSOD activities obtained from this preliminary study, seems to be more explicative in the identification of a pathological from a healthy tissue. SOD in GTA samples present a trend similar to healthy tissues, although in HP seems to be nearly to adenocarcinoma. Further researches will be necessary to define the role of SODs in cancer and the use of the activity as a prognostic marker.

We expand here the description of the Antarctic temperature variability during the long interglacial period occurring ~400 thousand years before present (Marine Isotopic Stage, MIS 11). This is achieved thanks to new detailed deuterium measurements conducted on the EPICA Dome C ice core, Antarctica, with a ~50 year temporal resolution. Despite an ice diffusion length reaching ~8 cm at MIS 11 depth, the data allow to highlight a variability at multi-centennial scale for MIS 11, as it has already been observed for the Holocene (MIS 1). Differences between MIS 1 and MIS 11 are analysed regarding the links between multi-millennial trends and sub-millennial variability. The EPICA Dome C deuterium record shows an increased variability and a shift in the observed periodicities at the onset of the final cooling phase of MIS 11, with stronger millennial to multi-millennial variability. Our findings are robust with respect to sensitivity tests on the somewhat uncertain MIS 11 duration.

A high-resolution deuterium profile is now available along the entire European Project for Ice Coring in Antarctica Dome C ice core, extending this climate record back to marine isotope stage 20.2, ~800,000 years ago. Experiments performed with an atmospheric general circulation model including water isotopes support its temperature interpretation. We assessed the general correspondence between Dansgaard-Oeschger events and their smoothed Antarctic counterparts for this Dome C record, which reveals the presence of such features with similar amplitudes during previous glacial periods. We suggest that the interplay between obliquity and precession accounts for the variable intensity of interglacial periods in ice core records. Northern and Southern hemisphere, methane, ice cores, Greenland, Antarctica, EPICA, Dansgaard–Oeschger events, Atlantic meridional overturning circulation.

[1] Water stable isotope measurements (δD and δ18O) have been conducted on the Holocene part of two deep Greenland ice cores (Greenland Ice Core Project (GRIP) and NorthGRIP), located ∼320 km apart. These combined measurements provide the first two continuous Greenland Holocene deuterium excess profiles (d = δD − 8δ18O), a parameter strongly influenced by changes in moisture sources. We discuss here temporal and regional fluctuations of the deuterium excess within central to north Greenland, with a mean temporal resolution of ∼4 years. Although GRIP and NorthGRIP exhibit similar annual mean surface temperatures and δ18O levels, a significant offset of modern deuterium excess is observed between the two sites. We attribute this offset to a different mix of modern moisture sources, pointing to regional-scale differences in moisture advection toward Greenland. The common long-term deuterium excess Holocene increasing trend is probably related to the increased relative contribution of low-latitude moisture to Greenland snowfall, in response to the change in the Earth obliquity, as symmetrically observed in Antarctica. Three abrupt declines punctuate the GRIP excess record (8.2, 4.5, and 0.35 ka BP), suggesting associated reorganizations of the northern high latitudes hydrological cycle. The 8.2 ka BP event is characterized by (1) a rapid cooling followed by a progressive warming and (2) a deuterium excess cooling restricted to GRIP, therefore totally different from rapid events during glacial times. By contrast, the NorthGRIP deuterium excess record is more stable. We propose that a slightly larger proportion of moisture supplied by local storm tracks to GRIP induces an isotopic compensation mechanism between simultaneous site and source temperature coolings, resulting in a rather temperature-insensitive δ18O profile, together with well-marked deuterium excess amplitudes. NorthGRIP δ18O seems less biased by isotopic processes and should provide a more reliable past temperature record.

The concentrations of heavy metals Hg, Pb and Cd found in zooplankton samples collected in two stations off Cesenatico (Northern Adriatic Sea) from March 1978 to January 1979, have been reported. The Hg, Pb and Cd concentrations showed large variations which did not seem to be correlated with taxonomic composition. The detected levels of metals were higher at the offshore than the nearshore station, accordingly with the sediment pattern. The high concentration of Hg were apparently associated with sources of local industrial pollution.

pp'DDT was converted to DDD 1-1 dichloro-2,2 bis (p-chlorophenyl) ethane, by treated 12 000 x g supernatant preparations from grey mullet livers. The anaerobic reductive dechlorination occurs whether or not exogenous NADPH and riboflavin is added after a heat pretreatment, otherwise the dechlorination is lowered when the cofactors are not added.

The effects of high temperatures on the clam, Chamelea gallina, generally recognised as a low tolerant bivalve species, were studied by evaluating some functional responses of the haemocytes. The animals were kept for 7days at 20, 25 and 30 degrees C and total haemocyte count (THC), phagocytosis, lysozyme activity (in both haemocyte lysate and cell-free haemolymph), activity and expression of the antioxidant enzyme superoxide dismutase (SOD) (in both haemocyte lysate and cell-free haemolymph) were chosen as biomarkers of exposure to high temperatures. The survival-in-air test was also performed. During the experiment, the clams showed differing burrowing behaviour: the animals kept at 20 and 25 degrees C burrowed completely, whereas at 30 degrees C the clams progressively emerged from the sediment and then remained on the surface. The highest temperature significantly increased THC, whereas it decreased the phagocytic activity of haemocytes. The haemocyte size frequency distribution in clams kept at 30 degrees C showed that the cell population of about 8-10microm was markedly reduced compared to clams kept at 20 and 25 degrees C. In clams maintained at 25 degrees C, lysozyme activity was significantly increased in haemocyte lysate, whereas it was markedly decreased in cell-free haemolymph. Total SOD activity significantly decreased in haemocytes from clams held at 30 degrees C whereas it increased in cell-free haemolymph from clams held at 25 degrees C and 30 degrees C. A significant decrease in haemocyte Mn-SOD and Cu/Zn-SOD activities was found with increasing temperature. In cell-free haemolymph, the highest Mn-SOD activity was recorded at 30 degrees C, whereas the Cu/Zn-SOD activity showed no significant changes in clams maintained at different temperatures. SOD isoform expression exhibited different patterns in haemocyte lysate and cell-free haemolymph. The resistance to air exposure of clams kept at 30 degrees C was shown to decrease significantly, LT(50) values fell from 6days in clams kept at 20 degrees C and 25 degrees C to 4days in those kept at 30 degrees C.

A contribution from members of the PAGES Past Interglacials (PIGS) Working Group. ABSTRACT: Whereas millennial to submillennial climate variability has been identified during the current interglacial period past interglacial variability features remain poorly explored because of lacking data at sufficient temporal resolutions. Here we present new deuterium data from the EPICA Dome C ice core documenting at decadal resolution temperature changes occurring over the East Antarctic plateau during the warmer than today last interglacial. Expanding previous evidence of instabilities during the last interglacial multicentennial subevents are identified and labeled for the first time in a past interglacial context. A variance analysis further reveals two major climatic features. First an increase in variability is detected prior to the glacial inception as already observed at the end of Marine Isotopic Stage 11 in the same core. Second the overall variance level is systematically higher during the last interglacial than during the current one suggesting that a warmer East Antarctic climate may also be more variable.

The effects of water-borne exposure to benzo[a]pyrene (36 hrs; celite-bound 0.44 mg L-1 B[a]P) on cytochrome P450 (CYP) and superoxide dismutases (SODs) were examined in digestive gland of the blood clam, Scapharca inaequivalvis. B[a]P accumulation and elimination were rapid, with maximum whole-body concentrations of 1.78 ng g-1 wet wt. after 12 hours of treatment, followed by a progressive decline to 0.89 ng g-1 at 36 hours. The presence of B[a]P resulted in an increase in total CYP of digestive gland microsomes from 54 ± 14 to 108 ± 21 pmol mg-1 protein (mean ± SD; p

In the present study, the effects of high temperatures on immune responses in the clam Chamelea gallina (Bivalvia: Veneridae) were evaluated.

Gastric cancer is the second most common cancer worldwide. The involvement of reactive oxygen species (ROS) in the pathogenesis of gastric malignancies is well known. Many human tumours have shown significant changes in the activity and expression of superoxide dismutase (SOD), which might be correlated with clinical-pathological parameters for the prognosis of human carcinoma. The aim of this study is the detection of MnSOD and CuZnSOD activity and their expression in gastric adenocarcinoma and healthy tissues. Gastric samples (adenocarcinoma and healthy tissues) harvested during endoscopy or resected during surgery were used to determine MnSOD and CuZnSOD activity and expression by spectrophotometric and Western blotting assays. The total SOD activity was significantly higher (p

The major animal responses to acute shock are known to involve changes in gene transcription and translation of heat shock protein (HSPs) . HSPs show different roles as chaperones in normal and damaged protein folding and in maintenance of receptor conformation. Marine littoral invertebrates tolerate a remarkable array of natural stresses, including anoxia, thermal and osmotic fluctuations. Several of these environmental stresses are responsible of HSP induction, that contribute to the tolerance of otherwise lethal conditions. This study was aimed at detecting HSP70 expression in Chamelea gallina tissues in response to oxygen, temperature and salinity changes.

I ROS rivestono un importante ruolo microbicida e allo stesso tempo sono responsabili di molteplici danni a diverse macromolecole biologiche (stress ossidativi). Per contrastare lo stress ossidativo gli organismi aerobi dispongono di sistemi di difesa. In particolare la superossido dismutasi (SOD) è il principale enzima coinvolto nella dismutazione dello ione superossido (O2-•). Dal momento che le variazioni della tensione di ossigeno e della temperatura sono responsabili di potenziali rischi immunologici, con la presente ricerca ci proponiamo di valutare gli effetti della anossia/riossigenazione e della temperatura sull'attività ed espressione della SOD negli emociti del bivalve Chamelea gallina.

In order to investigate the influence of anoxic stress on haemocyte immune response, specimens of Chamelea gallina were exposed to 24 and 48 h anoxia. To evaluate recovery capacity clams were maintained, at the end of the anoxic phase, for 24 h in reoxygenated seawater. In this paper activity and expression of the antioxidant enzyme superoxide dismutase (SOD) were studied on haemocyte lysate and haemolymph. Reported results have shown that the anoxic stress changed strongly the response of Chamelea gallina blood cells. Indeed, at the end of the anoxic phase in both experiments (24 and 48 h of anoxia exposure) SOD activity in haemocyte lysate decreased significantly with respect to the control, likely because of a decreasing superoxide anion generation in anoxia. Expression analyses were coherent with activity values. In the first experiment (24 h anoxia) reoxygenation determined an increase in activity of both Cu/Zn-SOD and Mn-SOD, but with values that remained significantly lower than those of the controls. It seems that after the applied anoxic stress, 24 h of recovery is not sufficient to restore pre-anoxic conditions. In the second experiment (48 h anoxia), SOD isoforms showed a different response during the recovery of animals. Cu/Zn-SOD activity dropped below the values showed by haemocytes of anoxic bivalves, while Mn-SOD activity values exceeded significantly those of controls . The different haemocyte response could be probably due to a further stress suffered by the clams because of a massive spawning during the reoxygenation phase. Therefore the high values of activity shown by Mn-SOD during the recovery is likely to be due to the high inducibility of this isoform . In Cu/Zn-SOD expression analyses two immunoreactive bands were highlighted in both experiments. The former (apparent molecular weight of 16 kDa), corresponds to the expression of SOD1 and the latter (apparent molecular weight of 28-30 kDa) could be attributed to EC-SOD (SOD3), a Cu/Zn-SOD isoform located in extracellular ambient and identified both in vertebrates and invertebrates. The strong SOD3 expression during anoxia exposure and the further spawning stress (second experiment) testified its inducibility in C. gallina haemocytes and haemolymph in response to stressful conditions.

Aim: reactive oxigen species (ROS) have a well-estabilished role in the athogenesis of many forms of malignancy and superoxide dismutase(SODs) are the only enzymes dismuting one of the main radicals: the superoxide anion. Since many human tumors have shown significant changes in the activity and expression of SODs, this enzyme might be correlated with survival and clinical-pathological parameters for the prognosis of human carcinoma. This preliminary study were performed to assess the SODs(CuZnSOD and MnSOD) activity and expression in gastric adenocarcinoma with respect to healthy tissue using western blotting (W-B) technique as a specific and sensible clinical test.

The effects of anoxia on the immune responses of a commercially important bivalve species, Chamelea gallina, were studied in two different experiments (24-h and 48-h exposure to deoxygenated seawater). After anoxic stress, the capability of clams to recover was also evaluated by maintaining animals for 24 h in aerated seawater. Total haemocyte count (THC), phagocytosis and lysozyme activity (in both haemocyte lysate and cell-free haemolymph) were chosen as cellular biomarkers of exposure to anoxic conditions. Anoxia significantly reduced THC with respect to controls in both experiments. However, clams which recovered from the 24-h anoxia test showed THC values similar to those of controls, whereas in the 48-h test recovery clam THC was similar to that of stressed clams. Significantly decreased phagocytic activity with respect to controls was also observed in both experiments. In the first experiment, haemocytes from recovery clams showed slightly higher phagocytic activity with respect to controls, whereas after 48 h of exposure haemocytes from recovery animals were unable to recover their phagocytic activity. After both 24-h and 48-h anoxia, lysozyme activity was significantly reduced in both haemocyte lysate and cell-free haemolymph. In recovery clams from 24-h anoxia, the lysozyme activity of lysate was significantly lower than in control and stressed clams, whereas in haemolymph it was significantly higher. Conversely, in recovery clams from 48-h anoxia, the enzyme activity of both media decreased significantly with respect to controls. Interestingly, an unexpected additional stress during the 48-h anoxia test was recorded: recovery clams spawned during the recovery phase. To validate the hypothesis that spawning acts as an additional type of stress, the survival-in-air test was also performed. Significant decreases in resistance to air exposure were observed after 48 h anoxia in both stressed and recovery animals. Results show that anoxia strongly affects the functional responses of haemocytes, reducing immunosurveillance in stressed clams. The present study also highlights that additional stress, such as spawning, may further decrease immunosurveillance and reduce the resistance of clams to exposure to air.

Nel presente lavoro è stata monitorata l’attività della SOD, come importante biomarker di alterazioni dovute alla variazione del tenore di ossigeno, nel Mollusco Bivalve Tapes philippinarum (euriossico) in seguito ad anossia e riossigenazione, utilizzando tecniche enzimatiche e immunologiche.

Hypoxia and anoxia are stress conditions that may affect physiological and biochemical responses in infaunal marine organisms, such as bivalves. Depending on the species, bivalves generally show a variable tolerance (measured as anoxic survival response) to hypoxia/anoxia periods, according to ability of organisms to modulate their metabolism. Low oxygen conditions have also been shown to affect bivalve immune responses (Hawkins et al., 1993; Pampanin et al., 2002). In this work, the effects of anoxia on functional responses of haemocytes were investigated in the commercially important species, Chamelea gallina. The capability of clams to recover after anoxic stress was also evaluated. Total haemocytes count (THC), phagocytosis and lysozyme activity were chosen as cellular biomarkers of exposure to anoxic conditions

The immune system of the animals consists of cellular and humoral elements involved in defence mechanisms from pathogens, parasites and foreign elements. Concerning to invertebrates, the immune responses are mediated by haemocytes through several internal defence mechanisms. As mammalian monocytes and macrophages, bivalve haemocytes show high phagocytosys activity versus non-self molecules and cells. Haemocytes activation determines an increasing oxygen consumption (respiratory burst) resulting in a reactive oxygen species (ROS) generation, that play a very important role in microbiocidal activity. However an excess of ROS production during an infection, can be dangerous for the cells, causing lipid peroxidation and DNA damages. The cell defence versus oxidative stress rely on enzymatic and non-enzymatic antioxidant systems. The superoxide dismutase (SOD) is one of the main enzyme involved in antioxidant activity. In this research will be evaluated the production of ROS (indirectly through SOD activity detection) by Chamelea gallina haemocytes during anoxia and following recovery and its role in immune responses.